Look at the facts here. It's got Rocket Raccoon. It's a free-to-play PC game, especially if you like playing Daredevil, Storm, The Thing, Scarlet Witch or Hawkeye, the five characters included at no cost. It's got Rocket Raccoon. It plays like Diablo II, which many consider the sweet spot for the action RPG franchise. It's a great deal of fun.
Oh, and it has Rocket Raccoon in it.
Considering the regular hero injections in Gazillion's Super Hero Squad Online, if one of Marvel Heroes' 26 starters don't float your boat, odds are better ones like Squirrel Girl and Moon Knight won't be missing for long.
So that's a yes. The game is definitely worth a bit of your hard disk space, as long as you aren't worried about the compulsion to buy all of the free-to-play-funding microtransaction things. Just go try it, and if you see Fahey the Rocket Raccoon running around, know that I'm probably talking to you, even if you can't hear me.